1. Field of the Invention
The present invention relates to a radiation image capturing system and a method of capturing a radiation image of a subject by applying a radiation from a radiation source through the subject to an image capturing apparatus.
2. Description of the Related Art
In the medical field, there have widely been used radiation image capturing apparatus which apply a radiation to a subject and guide the radiation that has passed through the subject to a radiation conversion panel, which captures a radiation image from the radiation.
One known radiation conversion panel is a stimulable phosphor panel which stores a radiation energy representative of a radiation image in a phosphor. When the stimulable phosphor panel is irradiated with stimulating light, the phosphor emits stimulated light representative of the stored radiation image. The stimulable phosphor panel with the radiation image recorded therein is supplied to a reading apparatus which reads the stored radiation image as a visible radiation image.
In sites of medical practice such as operating rooms or the like, it is necessary to read recorded radiation image immediately from a radiation conversion panel for the purpose of quickly and appropriately treating the patient. As a radiation conversion panel which meets such a requirement, there has been developed a direct-conversion radiation conversion panel for directly converting a radiation into an electric signal or an indirect-conversion radiation conversion panel for converting a radiation into visible light with a scintillator and then converting the visible light into an electric signal to read a detected radiation image.
The radiation image capturing apparatus should desirably be capable of capturing a radiation image of a given body region of a patient accurately and reliably for thereby reducing burdens on the patient while the radiation image thereof is being captured.
According to the proposal disclosed in Japanese Laid-Open Patent Publication No. 2001-504013 (PCT), a reflective marker is applied to a patient at a give position thereon, and then light is applied from an infrared stroboscopic source to the patient. Light reflected from the reflective marker is detected by a camera device, and an X-ray apparatus (image capturing apparatus) is positioned with respect to the patient based on the light detected by the camera. Japanese Laid-Open Patent Publication No. 2001-346796 discloses a positioning adjuster wherein the head of a patient guided into an image capturing apparatus is imaged by a front camera and a side camera, various parts of the image capturing apparatus are automatically adjusted to accurate positions with respect to the head of the patient based on face image data of the patient from the cameras, and the patient is instructed to move the head.
According to the technologies disclosed in Japanese Laid-Open Patent Publication No. 2001-504013 (PCT) and Japanese Laid-Open Patent Publication No. 2001-346796, before a radiation image of the patient is captured, the position of the image capturing apparatus with respect to the patient is adjusted, or the position of the patient is moved into alignment with the image capturing apparatus, so that a radiation image of a given body region of the patient can accurately be obtained.
When the radiation image is captured, the radiation is applied from the radiation source through the patient (subject) to the image capturing apparatus including the radiation conversion panel. Therefore, before the radiation image is captured, it is necessary to determine whether the positional relationship between the image capturing apparatus and the subject is proper or not, and whether the positional relationship between the radiation source and the image capturing apparatus is proper or not, or more specifically, whether the radiation source is oriented toward the image capturing apparatus or not.
In other words, a processor for controlling the process of capturing the radiation image controls the image capturing apparatus based on an image capturing mode which is indicative of image capturing conditions for capturing the radiation image. If a plurality of image capturing apparatus are available for capturing a radiation image of a subject, then when one of the image capturing apparatus which is controlled by the processor to capture the radiation image based on the image capturing mode is different from another one of the image capturing apparatus toward which the radiation source is oriented, the radiation image of the subject cannot be obtained accurately and reliably.